Dispersal in a metapopulation of the bush cricket, Metrioptera bicolor (Orthoptera: Tettigoniidae)

Abstract

1. I present a stochastic simulation model that describes individual movements of Metrioptera bicolor Philippi in a heterogeneous landscape, consisting of patches of suitable habitat surrounded by a matrix of unprofitable habitats. Although the model is parameterized with information about daily movement behaviour, it can generate: spatially explicit predictions about inter-patch dispersal rates for much longer periods, e.g. one generation. 2. Long-term dispersal experiments were conducted to evaluate model predictions. Patch-specific emigration rates and the total distance moved by individuals could be predicted with satisfactory precision. Because of the stochastic nature of the model, it failed to predict which recipient patches emigrating individuals actually chose in a particular situation. 3. Spatially explicit simulations of the movement model were made for the whole natural distribution area of M. bicolor. The results suggest that emigration rates are negatively correlated with patch size. Local populations occurring on small patches may be more prone to extinction than those on large patches, by losing more emigrants than are compensated for by immigration.